Lorries at the shipping cargo terminal of Dover. New customs checks could gridlock the port
Photograph: Felix Clay for the Guardian

The introduction of customs checks at Dover after Britain leaves the EU could bring gridlock to the south-east of England, with lorries queueing for up to 30 miles in Kent to get across the channel, senior figures in the transport industry have warned.

Short of cutting into the famous Cliffs of Dover, the busy cargo port has no room to expand to accommodate paperwork checks for the 2.6m trucks that pass through the port every year.

Eurotunnel, which caters for another 1.6m lorries a year at its Euroshuttle transporter a few miles inland, is facing the same problem.

John Keefe, its spokesman, said: “On one side of Eurotunnel we have an area of outstanding beauty, so you can’t build to the left, and on the right we have the motorway; then you have to look at moving up, down, or back along the motorway.”

The problem for business is not just the prospect of tariffs in a new customs regime but the disruption to the free flow of goods. “There are no warehouses any more, everything is about ‘just in time’,” says Keefe, referring to a strategy for managing goods that ensures they arrive only shortly before they are needed in order to reduce costs.

Drivers with their documentation inside the freight clearance offices at Dover. Photograph: Felix Clay for the Guardian

A bottleneck in Dover would affect businesses from the car industry in the Midlands to farmers in Wales and fisheries in Scotland.

In the summer of 2015, a French ferry workers strike led to more than 7,000 trucks backed up the motorway almost as far as Maidstone. With as many as 16,000 trucks a day using Dover, the potential for a repeat of that episode alarms business.

“If you are looking at stopping trucks, you are looking at stopping the economy,” says Keefe.

Businesses lost £21m-worth of stock due to the traffic chaos in 2015. Live shellfish destined for Paris markets and other perishable goods were dumped because of the delays, said the Road Haulage Association (RHA).

An emergency traffic management strategy at the time, called Operation Stack, is estimated to have cost the Kent economy £1.5m a day, with parts of the M2 turned into a vast lorry park.

“It is absolutely critical that UK customs takes this issue seriously and is prepared to handle it from day one because even one day’s delay is disruption to the supply chain and costs to trade,” said Jack Semple, the director of policy at the RHA. “We do not believe that HMRC is at all resourced to do this at the moment.”

Michael Lux, a customs trade lawyer who recently gave evidence to a Commons select committee on the challenges facing Theresa May on the border in Ireland, said the paperwork alone was going to add administration time to businesses, with all cargo required to have a customs licence or “export declaration” form.

UK exporters could be processed in blue and green lorry lanes to speed up traffic, but this would require investment in infrastructure, and space that is virtually non-existent in Dover.

Asked if the UK would be ready for a reintroduction of customs in two years, Lux replied: “You make me laugh. You will need at least double the number of customs officials than you have now. They will need to be recruited and trained and this takes time”.

Tim Dixon, a freight clearance operator at Motis in the Western Docks, deals with non-EU trucks in Dover. He says many customs experts in the port retired or were made redundant when trade barriers were lifted in 1992.

“There used to be 120 agents based in Dover before 1992, and now we have less than 30. Just doing the paperwork could be a nightmare,” he said.

Semple has called on the government to urgently engage with business before it is too late. If trucks coming from the EU are treated like non-EU trucks in future, the port will be in permanent gridlock, say local customs experts.

This is a headwind we did not need and is not welcome. It’s a bleak picture

Neal Williams

“With Brexit, we are potentially coming full circle, but we cannot return to the systems pre-1993, or the southern road corridor would bring the UK to a halt,” he said. “We need the government to prepare for the worst and plan for the best outcome. What is crucial is to keep port, tunnel and roads free running. This requires them to engage now, invest early and involve the local knowledge.”

One option would be to have clearance points further inland.

Neal Williams, the managing director of Priority Freight, a haulier offering express freight to international companies, suggested: “Maybe you could have multiple customs checks around the country. But everything would have to be planned, phased in, impact studies conducted, implementation studies done and there would have to be the infrastructure for trucks to make the customs stop.”

Another, perhaps more elegant solution, would be to do both import and export customs clearance in Calais. “That way you wouldn’t need two stops,” said Lux.

British police already conduct passport checks in Calais – extending that to include customs checks would require talks with France.

Charlie Elphicke, the Conservative MP for Dover and Deal, believes the solution is electronic checks. He said he was consulting with local businesses and experts such as the former head of Border Force and consultants at Accenture to come up with a proposal in the spring.

Whatever path is ultimately taken, May’s outline of her hard Brexit intentions has Dover and all UK ports on a nervous countdown. “Two years? it might as well be two minutes,” said Andrew Austin, of Priority Freight.

Experts say the port has nowhere to expand if new warehouses and checkpoints are needed. Photograph: Felix Clay for the Guardian

To ease the transition, the UK could adapt a “trusted trader” status such as that which operates on the Mexican/US border, Lux said. This would allow “clean” companies, such as large brand suppliers and carmakers, to be waved through without the risk of random checks for “misdeclared” cargo.

But this will not help trucks that pick up cargo from different suppliers.

“Customs and freight agents would need a vast amount of additional staff to cope with the volume of vehicles that will require customs clearance. If the load consists of cargo destined for various importers in the UK, there is a possibility that this could be covered by over 50 transit documents that require processing,” said Dixon.

Williams predicted that Britain would “muddle through”, but he is concerned that there is no support from any government body, no engagement with business or the town and no sense that anyone has been assigned to working on a contingency plan.

His company already switches to air cargo when the port or tunnel are disrupted, but he said the unknowns were preventing businesses from planning their futures: “We don’t mean to be so downbeat, but this is a headwind we did not need and is not welcome. It’s a bleak picture.”